Exits and blocked exits

Rooms connect with direction lines. Ten directions exist: the eight compass points plus up and down. A plain exit connects both ways: the return exit is inferred in the opposite direction, so north to the Herb Garden on the Rose Walk also puts a south exit on the Herb Garden. Write , one-way for an exit with no way back — a landing the story reaches only by moving the player there, and leaves by walking:

create Behind the Fruit Stall
  a room
  southwest to the Fruit Stall, one-way

The same modifier works on a door line (north to the Hall through the oak door, one-way): the door opens from the written side only.

create the Rose Walk
  a room
  north to the Herb Garden
  east to the Orchard
  south is blocked: hedge-too-thick

  Gravel crunches underfoot between the rose beds.

A blocked exit refuses travel and speaks the named phrase (the key after the colon names a phrase the story defines, a single kebab-case word; dots are illegal, ADR-254). The block can be conditional:

create the Orchard
  a room
  west to the Rose Walk
  up is blocked while the ladder is not here: no-way-up

  Apple trees stand in crooked rows.